CN111266421B

CN111266421B - Aluminum steel composite material, preparation method thereof and power station air cooling equipment

Info

Publication number: CN111266421B
Application number: CN202010075176.9A
Authority: CN
Inventors: 伍波; 郭耿锋; 周德敬
Original assignee: Yinbang Clad Material Co Ltd
Current assignee: Yinbang Clad Material Co Ltd
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2022-04-12
Anticipated expiration: 2040-01-22
Also published as: CN111266421A

Abstract

The application relates to an aluminum steel composite material, a preparation method thereof and power station air cooling equipment. Wherein, aluminium steel composite includes: performing salt bath nitriding treatment, namely performing salt bath nitriding treatment on the steel plate; and rolling and compounding the steel plate subjected to the salt bath nitriding treatment and the aluminum plate. After the surface of the steel layer is subjected to salt bath nitriding treatment, a micron-sized compound layer formed on the surface is easy to break in the subsequent rolling treatment process, and firmer physical occlusion is formed.

Description

Aluminum steel composite material, preparation method thereof and power station air cooling equipment

Technical Field

The application relates to the field of layered composite materials, in particular to an aluminum-steel composite material, a preparation method thereof and power station air cooling equipment.

Background

The aluminum-steel layered composite material has the advantages of light weight, corrosion resistance, good electric and heat conducting properties of aluminum, high strength of steel, low cost and the like. The aluminum steel composite material is widely applied to the fields of aerospace, machinery, chemical engineering, food and the like. However, due to the large difference in physical and chemical properties of aluminum and steel, particularly the large difference in melting point and mechanical properties, and the characteristic of generating intermetallic compounds at high temperature, the method has raised requirements for the production of aluminum/steel composite strips and the application of aluminum/steel composite strips under high temperature brazing conditions of over 600 ℃, so that the improvement of the interface bonding strength of aluminum and steel and the critical temperature of interface intermetallic compound generation are always the main directions of industrial research.

The above information disclosed in this background section is only for enhancement of understanding of the background of the application and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.

Disclosure of Invention

The application provides a preparation method of an aluminum steel composite material, which comprises the steps of carrying out salt bath nitriding treatment on a steel plate, forming a layer of iron-nitrogen compound layer on a steel layer, and then carrying out rolling compounding on the iron-nitrogen compound layer and an aluminum plate to obtain a composite plate with higher interface bonding strength and higher critical temperature of an interface intermetallic compound formed by high-temperature annealing.

According to one aspect of the application, the preparation method of the aluminum steel composite material comprises the following steps: performing salt bath nitriding treatment, namely performing salt bath nitriding treatment on the steel plate; and rolling and compounding the steel plate subjected to the salt bath nitriding treatment and the aluminum plate.

According to some embodiments of the present application, the salt bath nitriding treatment is preceded by: and (5) polishing, namely polishing the steel plate by using an abrasive belt.

According to some embodiments of the present application, the steel sheet comprises a low carbon steel sheet.

According to some embodiments of the present application, the salt bath nitriding treatment conditions include: the temperature is 580 ℃ and 640 ℃, and the time is 30-150 minutes.

According to some embodiments of the present application, the salt bath nitriding treatment further comprises: taking out the steel plate subjected to nitriding treatment, and cooling; cleaning the steel plate subjected to cooling treatment; and drying the cleaned steel plate.

According to some embodiments of the present application, after the salt bath nitriding treatment, an Fe — N compound is generated on the surface of the steel sheet.

According to some embodiments of the present application, the Fe-N compound has a thickness of 2 to 15 micrometers.

According to some embodiments of the present application, the aluminum plate comprises: commercial purity aluminum or low alloyed aluminum alloy sheet.

According to some embodiments of the application, the rolling process comprises: and (5) single-pass cold rolling compounding.

According to some embodiments of the present application, the single pass cold rolling compounding conditions comprise: the cold rolling composite reduction is 50-60%.

According to some embodiments of the present application, after the rolling composite process, the method further comprises: and (4) annealing treatment, namely performing diffusion annealing treatment on the aluminum steel composite material.

According to some embodiments of the present application, the diffusion annealing treatment conditions include: the annealing temperature is 520-550 ℃, and the annealing time is 10-24 hours.

According to another aspect of the application, an aluminum steel composite material is further provided, and is prepared by the preparation method.

According to another aspect of the application, the power station air cooling equipment comprises the aluminum steel composite material.

The application of the scheme of each embodiment of the application can improve the interface bonding strength of the aluminum steel composite material, and irreversible intermetallic compounds are not easy to generate under the high-temperature condition. The aluminum steel composite material prepared by the method enables the bonding performance of the aluminum steel strip to be more excellent than that of the aluminum steel composite material which is not prepared by the method, and has very important significance for popularizing the application range of the aluminum steel laminated composite material.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:

FIG. 1 is a flow chart of a method of making an aluminum steel composite material according to an exemplary embodiment of the present application;

FIG. 1-A is an X-ray diffraction (XRD) pattern of compounds generated after salt bath nitriding treatment of a steel sheet to be clad according to an exemplary embodiment of the present application;

FIG. 2 is a flow chart of a method of making an aluminum steel composite material according to another exemplary embodiment of the present application;

FIG. 3 is a metallographic photograph of a cross section of a nitrided steel plate according to an exemplary embodiment of the present application;

FIG. 4A is an SEM of the interface of a composite material after cold rolling according to an exemplary embodiment of the present application;

FIG. 4B is a scanning electron microscope photograph of the interface of a cold rolled composite of steel sheet and aluminum sheet without nitriding treatment according to comparative example of the present application;

FIG. 5A is a 200 magnification interfacial metallographic picture of an aluminum steel composite material according to an exemplary embodiment of the present application after annealing;

FIG. 5B is a 500 magnification interfacial metallographic picture of an aluminum steel composite material according to an exemplary embodiment of the present application after annealing;

FIG. 6A is a 200 magnification interfacial metallograph of an aluminum steel composite annealed according to a comparative example of the present application;

FIG. 6B is a 500 Xmagnification interfacial metallograph of an annealed aluminum steel composite of a comparative example of the present disclosure;

FIG. 7 is a bar graph of peel strength versus control according to an exemplary embodiment of the present application.

List of reference numerals:

301 compound layer

401 aluminum layer

403 steel layer

405 compound layer

407 aluminum layer

409 steel layer

501 aluminum layer

502 steel layer

503 compound layer

601 aluminium layer

603 steel layer

605 intermetallic compound

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present application. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the description of the present application, it is to be understood that the terms "longitudinal," "width," "thickness," "upper," "lower," and the like refer to an orientation or positional relationship based on that shown in the drawings, which is for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it is to be noted that the terms "contacting," "connecting," and "connecting" are to be construed broadly and may be, for example, directly or indirectly through intervening media, unless expressly stated or limited otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

In the production process of the metal laminar composite material, the metal surface state plays a very important role. Four layers of substances are sequentially arranged on the surface of the metal from outside to inside, and the four layers of substances comprise an adsorption layer, an oxidation layer, a transition layer and a collector layer. The adsorption layer and the oxidation layer are the main surface factors influencing the recombination of the metal interface. Only the adsorption layer and the oxidation layer on the surface of the metal to be compounded are cleaned, and a hardened layer is formed on the surface of the metal, and in the rolling compounding process, the hardened layer is broken, the fresh component metals are in direct contact, and firm interface combination is formed through certain plastic deformation. When the aluminum steel composite strip is produced, an online surface treatment technology, such as steel wire brush or abrasive belt polishing, is usually adopted to manufacture a continuous and stable fresh interface to be compounded, so that the continuous and stable compounding of the aluminum steel interface in the aluminum steel composite strip is realized. However, the hardened layer on the surface of the steel layer after on-line polishing treatment is only 2-3 microns, and the hardened layer is easy to break, so that fresh aluminum and steel metal contacts and generates cooperative plastic deformation, the aluminum and steel interface is relatively flat, and the interface bonding strength is limited.

At present, the interface bonding strength of the 4A60 aluminum alloy/08 Al steel composite strip is limited, and an irreversible, hard and brittle intermetallic compound is easily generated at the temperature of more than 600 ℃, so that the bonding property of the aluminum steel strip is deteriorated, even an aluminum layer is likely to fall off, and the mechanical property of the aluminum steel interface and the service life of a product are seriously influenced. The application aims at the problems by performing salt bath nitriding treatment on a 08Al steel plate and then performing cold rolling compounding on the 08Al steel plate and a 4A60 aluminum plate.

The exemplary embodiments of the present application will be described in conjunction with the accompanying drawings, and it should be understood that the exemplary embodiments described herein are merely for purposes of illustration and explanation and are not intended to limit the present application.

Examples

Fig. 1 is a flow chart of a method for preparing an aluminum steel composite material according to an exemplary embodiment of the present application.

Fig. 1-a is an X-ray diffraction (XRD) pattern of compounds generated after salt bath nitriding treatment of a steel sheet to be clad according to an exemplary embodiment of the present application.

Referring to fig. 1, according to an exemplary embodiment of the present application, a steel plate is first subjected to a grinding process S101, and the steel plate is ground with a belt. The steel plate is usually made of a low-carbon steel plate, in the embodiment, annealed 08Al steel with the thickness of 2.7 mm is selected, online abrasive belt grinding is performed on the steel plate, an 80 # abrasive belt is selected, an oil film on the surface is removed, the surface roughness of the steel plate is increased, and later rolling and compounding are facilitated. The average roughness of the polished 08Al steel plate in the polishing direction and the average roughness of the polished 08Al steel plate perpendicular to the polishing direction are respectively 1.316 micrometers and 7.611 micrometers.

At S103, salt bath nitriding treatment is performed, followed by transition to S105. IN this example, a 08Al steel sheet polished on-line was cut by wire into a test piece having a gauge of 100mm × 250mm, and the test piece was subjected to salt bath nitriding treatment IN an IN-80 QPQ salt bath nitriding furnace. According to the present exemplary embodiment, generally, the conditions of the salt bath nitriding treatment described above are: the temperature is 580 ℃ and 640 ℃, and the time is 30-150 minutes. In this example, a 08Al steel sheet was subjected to nitriding treatment in a salt bath nitriding furnace at a temperature of 600 ℃ for 1 hour to form Fe-N compounds on the surface of the steel sheet. As shown in FIG. 1-A, the above Fe-N compound is analyzed by X-ray diffraction (XRD), and Fe is reacted with the crystal form of the compound in which the diffraction peak of 2 theta diffraction angle is generated₃N corresponds well.

In S105, rolling is performed. The rolling treatment comprises the following steps: and rolling and compounding the steel plate subjected to the salt bath nitriding treatment and an aluminum plate. In this example, a 08Al steel sheet sample subjected to nitriding treatment was cold-rolled and clad in a single pass on a laboratory rolling mill with a 4A60 aluminum alloy sheet having a gauge of 1mm × 100mm × 250 mm. According to some embodiments of the present application, the aluminum sheet may optionally include engineered pure aluminum or a low-alloyed aluminum alloy sheet. In this embodiment, the diameter of the cold rolling composite work roll is 170mm, and the diameter of the back-up roll is 350 mm. According to the exemplary embodiment of the present application, the cold rolling compound reduction is between 50% and 60%, and in this embodiment, the cold rolling compound reduction is 60% and the rolling speed is 3 m/min.

Fig. 2 is a flow chart of a method of making an aluminum steel composite material according to another exemplary embodiment of the present application.

Referring to fig. 2, according to an exemplary embodiment of the present application, a step S201 of grinding a steel plate with a sandbag is first performed. In the embodiment, the annealed 08Al steel with the thickness of 2.7 mm is selected, and the steel plate is subjected to online abrasive belt grinding to remove an oil film on the surface and increase the surface roughness of the steel plate, so that the later rolling and compounding are facilitated. The average roughness of the polished 08Al steel plate in the polishing direction and the average roughness of the polished 08Al steel plate perpendicular to the polishing direction are respectively 1.316 micrometers and 7.611 micrometers.

As shown in fig. 2, in S203, the steel sheet subjected to the burnishing treatment is subjected to the salt bath nitriding treatment. IN this example, a 08Al steel sheet polished on-line was cut by wire into a test piece having a gauge of 100mm × 250mm, and the test piece was subjected to salt bath nitriding treatment IN an IN-80 QPQ salt bath nitriding furnace. According to the present exemplary embodiment, generally, the conditions of the salt bath nitriding treatment described above are: the temperature is 580 ℃ and 640 ℃, and the time is 30-150 minutes. In this example, a 08Al steel sheet was subjected to nitriding treatment in a salt bath nitriding furnace at a temperature of 600 ℃ for a period of 1 hour.

FIG. 3 is a metallographic photograph of a cross section of a nitrided steel sheet according to an exemplary embodiment of the present application.

Referring to FIG. 3, it can be seen from the profile of the nitrided steel sheet according to the exemplary embodiment of the present application that 301 generates Fe for the surface of the steel sheet₃An N compound layer having a thickness of about 2 to 15 μm.

Referring to fig. 2, according to an exemplary embodiment of the present application, in S205, a steel sheet subjected to salt bath nitriding treatment is subjected to a temperature reduction treatment, a cleaning treatment, and a drying treatment. In this example, a 08Al steel sheet was taken out of the salt bath nitriding furnace, oil-cooled, then cleaned with acetone, then cleaned with clear water, and blow-dried for use.

As shown in fig. 2, in S207, a steel sheet subjected to the salt bath nitriding treatment is roll-clad with an aluminum plate. In this example, a 08Al steel sheet sample subjected to nitriding treatment was cold-rolled and clad in a single pass on a laboratory rolling mill with a 4A60 aluminum alloy sheet having a gauge of 1mm × 100mm × 250 mm. According to some embodiments of the present application, the aluminum sheet may optionally include engineered pure aluminum or a low-alloyed aluminum alloy sheet. In this embodiment, the diameter of the cold rolling composite work roll is 170mm, and the diameter of the back-up roll is 350 mm. According to the exemplary embodiment of the present application, the cold rolling compound reduction is between 50% and 60%, and in this embodiment, the cold rolling compound reduction is 60% and the rolling speed is 3 m/min. After rolling treatment, some steel plate samples are used for metallographic observation experiments, and metallographic photos of the composite material are observed.

Referring to fig. 2, according to an exemplary embodiment of the present application, in S209, an annealing process, which performs a diffusion annealing process on an aluminum steel composite material, includes: the temperature is 520 ℃ and 550 ℃, and the annealing time is 10-24 hours. In this example, the aluminum steel composite sample plate obtained after cold rolling and compounding was placed in a KBF-1600 type box furnace for annealing at 530 ℃ for 15 hours. The rate of temperature rise was 10 deg.C/min. In order to determine the interfacial bond strength of the aluminum steel composite material after diffusion annealing in the cold rolling compounding machine, the test specimens were prepared to be usable for the peel strength test. In order to determine the generation condition of the interface intermetallic compound of the aluminum steel composite material at high temperature, the other sample prepared by the cold-rolled composite plate is put into a SK2-4-12 tube furnace for annealing treatment, and the annealing condition is that the temperature is kept at 630 ℃ for 1.5/3-4 hours. Before the annealing test, the hearth temperature of the sample placing area is subjected to temperature calibration by a FLUKE52 II type thermocouple, and the hearth temperature fluctuation is ensured to be within the range of +/-2 ℃. And similarly, carrying out metallographic observation on the interface of the aluminum steel composite material.

Comparative example

In the comparative example, annealed 08Al steel having a thickness of 2.7 mm was used as the steel sheet, and the same as in the example. Firstly, the steel plate is subjected to abrasive belt polishing to remove the surface oil film, so that the later rolling and compounding are facilitated. The roughness of the polished steel plate along the polishing direction and the roughness of the polished steel plate perpendicular to the polishing direction are the same as those of the steel plate provided in the embodiment, and details are not repeated here. Then, the steel plate samples and 4A60 aluminum alloy plates with the specification of 1mm multiplied by 100mm multiplied by 250mm in the examples are subjected to single-pass cold rolling compounding on an experimental rolling mill, the diameter of a working roll is phi 170mm, the diameter of a supporting roll is phi 350mm, the cold rolling compounding reduction is 60%, and the rolling speed is 3 m/min. After cold rolling, the aluminum steel composite material sample compounded by cold rolling is annealed in a KBF-1600 type box furnace under the annealing condition of 530 ℃, the annealing time is 15 hours, and the heating rate is 10 ℃/minute.

In order to determine the interface bonding strength of the aluminum steel after the rolling compounding and the diffusion annealing, and to compare the interface bonding strength with the aluminum steel composite material in the example, the metallographic observation interface, and the like, a sample for detection was prepared.

Fig. 4A is a scanning electron micrograph of a composite interface after cold rolling according to an exemplary embodiment of the present application.

Referring to fig. 4A, according to the exemplary embodiment of the present application, the interface morphology of the aluminum-steel composite material subjected to the salt bath nitriding treatment is easily seen, and a nitrided compound layer 405 between the aluminum-steel interface between the aluminum layer 401 and the steel layer 403 is broken to a large extent, and a significant mechanical interlocking occurs between the aluminum layer 401 and the steel layer 403. As shown in the enlarged detail view of fig. 4A, where the partial compound layer is broken to a lesser extent, the aluminum layer can also intrude into the compound layer 405 and engage the base steel layer.

FIG. 4B is a scanning electron micrograph of the interface of a cold rolled composite of steel sheet and aluminum sheet without nitriding treatment according to comparative example of the present application.

Referring to fig. 4B, it is apparent from the comparative example that the interface of the aluminum steel composite material prepared without the salt bath nitriding treatment is relatively flat, and no significant mechanical engagement is found between the aluminum layer 407 and the steel layer 409.

Fig. 5A is a 200 x magnification interfacial metallographic picture of an aluminum steel composite material according to an exemplary embodiment of the present application after annealing.

Fig. 5B is a 500 x magnification interfacial metallographic picture of an aluminum steel composite material according to an exemplary embodiment of the present application after annealing.

Referring to fig. 5A, according to the exemplary embodiment of the present application, the interface structure of the nitrided aluminum-steel composite material after annealing (at 630 ℃, for 3 hours) shows less intermetallic compound between the aluminum layer 501 and the steel layer 502, and the maximum thickness of the resulting intermetallic compound layer is about 20 μm.

As shown in fig. 5B, which is the high magnification interface morphology of fig. 5A, according to the exemplary embodiment of the present application, it can be seen that the intermetallic compound 503 is mainly present near the nitrided compound layer, and for the larger crack of the interface, almost no intermetallic compound is generated at the interface of the aluminum steel.

Fig. 6A is a 200 x magnification interfacial metallographic picture of an aluminum steel composite annealed according to a comparative example of the present application.

Fig. 6B is a 500 x magnification interfacial metallographic picture of an aluminum steel composite annealed according to a comparative example of the present application.

Referring to fig. 6A and 6B, in the comparative examples of the present application, the interface structure morphology of the aluminum steel composite material without nitriding treatment of the steel sheet with different magnification is shown, and it can be seen from the figure that after 1.5 hours under the annealing treatment condition of 630 ℃, a distinct intermetallic compound layer is formed on the aluminum steel interface, and the average thickness of the intermetallic compound is measured to be about 30 μm, which is in sharp contrast to the aluminum steel composite material in the examples of the present application in which no distinct intermetallic compound is formed after 3 hours of annealing treatment.

Referring to fig. 7, in order to determine the performance influence of the nitriding rolling composite treatment and the diffusion annealing treatment on the interface bonding strength of aluminum steel according to the exemplary embodiments and comparative examples of the present application and to compare the embodiments and comparative examples, the samples prepared in the above embodiments and comparative examples were cut into 10 mm × 120 mm peel tensile samples, three samples were taken, and the measured peel strength was averaged over the three results.

As shown in FIG. 7, the interface peel strength of the aluminum steel composite material with nitrided steel plate in the examples was 17.8N/mm, which is higher than that of the aluminum steel composite material with nitrided steel plate of 14.6N/mm. The peel strength of the aluminum steel composite material subjected to annealing treatment and nitriding treatment of the steel plate in the examples was 20.1N/mm, which is higher than that of the aluminum steel composite material subjected to annealing treatment and not subjected to nitriding treatment by 16.3N/mm. In the embodiment of the application, for the aluminum steel composite material with the nitrided steel plate, the interface peel strength of the aluminum steel composite material further subjected to annealing treatment is higher than that of the aluminum steel composite material without returning treatment.

By combining the examples and comparative examples of the present application, it can be seen that after the steel sheet is subjected to surface salt bath nitriding treatment, micron-sized Fe is formed on the surface₃The N compound layer is broken in the aluminum steel cold rolling compounding process and is expanded along the rolling direction, so that more fresh aluminum layers are promoted to be in contact with the steel layer, and a firmer physical occlusion structure is formed. Meanwhile, under the condition of high-temperature simulated brazing, the steel layer subjected to nitriding treatment improves the saturation degree of crystal lattices due to the penetration of nitrogen atoms, inhibits the diffusion of iron atoms, and ensures that an aluminum-steel interface is not easy to generate aluminum-iron intermetallic compounds.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Finally, it should be noted that: although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The preparation method of the aluminum steel composite material is characterized by comprising the following steps:

performing salt bath nitriding treatment, namely performing salt bath nitriding treatment on the steel plate;

rolling treatment, namely rolling and compounding the steel plate subjected to the salt bath nitriding treatment and an aluminum plate;

wherein the salt bath nitriding treatment conditions comprise: the temperature is 580-640 ℃, and the time is 30-150 minutes; the salt bath nitriding treatment is carried out IN an IN-80 QPQ salt bath nitriding furnace;

after the salt bath nitriding treatment, Fe is generated on the surface of the steel plate₃N。

2. The production method according to claim 1, characterized by, before the salt bath nitriding treatment, comprising: and (5) polishing, namely polishing the steel plate by using an abrasive belt.

3. The method of manufacturing according to claim 1, wherein the steel sheet comprises a low carbon steel sheet.

4. The production method according to claim 1, characterized by further comprising, after the salt bath nitriding treatment:

taking out the steel plate subjected to nitriding treatment, and carrying out cooling treatment;

cleaning the steel plate subjected to cooling treatment;

and drying the cleaned steel plate.

5. The method of claim 1, wherein the Fe is₃The thickness of N is 2 to 15 microns.

6. The method of manufacturing according to claim 1, wherein the aluminum plate includes: commercial purity aluminum or low alloyed aluminum alloy sheet.

7. The method of manufacturing according to claim 1, wherein the rolling process comprises: and (5) single-pass cold rolling compounding.

8. The method of manufacturing of claim 7, wherein the single pass cold rolling compounding conditions comprise: the cold rolling composite reduction is 50-60%.

9. The method of claim 1, further comprising, after the rolling process: and (4) annealing treatment, namely performing diffusion annealing treatment on the aluminum steel composite material.

10. The production method according to claim 9, wherein the diffusion annealing treatment conditions include: the annealing temperature is 520-550 ℃, and the annealing time is 10-24 hours.

11. An aluminium-steel composite material, characterized by being produced by the production method according to any one of claims 1 to 10.

12. A plant air cooling plant, characterized in that it comprises an aluminium-steel composite material according to claim 11.